I’m thinking of Getty Pygmy Cory’s, if I put sand in only one spot, will they use it?

So I have a 20 gal, planted, with 11 ember tetras. I would like some Pygmy Cory’s because they are so cute.

Right now my substrate is the fluval stratum. I’ve heard having sand is good for corys so if I dedicate 1/4 ish of the bottom capped with sand, will they use it or get hurt trying to sift through the other substrate?